1. Field of the Invention
The invention relates to a process for the preparation of fruits, berries and/or vegetables for the extraction of liquid raw products by comminuting the raw material and separating the juice pulp.
2. Description of the Related Art
For the production of juice pulp (pulpy juice) as a preliminary step for further refining measures it is known to use so-called pulping machines. The raw material to be processed which can consist of whole fruits is first crushed and then the juice is extracted in the pulping machine. In the course of this the juice pulp consisting of juice and cell material is separated from the seeds, stems, skins and cores by mechanical means.
This known process has the disadvantage that because of the intensive mechanical handling of the raw material in the pulping machine, especially in malaceous fruit. the stems, seeds and skin fragments are damaged, thereby causing a negative impact on the taste and aroma of the juice. Furthermore the residue consisting of stems, seeds, skins and cores which have been largely crushed by the pulping machine causes considerable difficulties in further extraction of juice by pressing. The overall yield is therefore smaller and the production of pulpy juices is uneconomical.
Generally known are also the conventional processes for extracting fruit juice by pressing. The object of these known methods is to achieve the highest possible yield with the lowest possible dregs content. Because of the dregs content work is done with a small mesh size, which, for example, in belt presses is about 0.5 mm. In this instance the fine dregs and valuable cell material remain in the residue of the press and are lost. Moreover the layer thickness of the pressed raw material with conventional belt presses is relatively great (approximately 30 to 50 mm). Because of this long juice paths are caused which do not let viscous cell material pass through which is needed for the extraction of juice pulp. The same is true for the passage openings in the separation wall between the juice which has flowed off and the residue, which are too small to let juice pulp through and would become clogged. The conventional pressing processes are therefore not suitable for the extraction of juice pulp, which along with the juice that has been squeezed out also still contains a large portion of cell material. The raw juice extracted from conventional presses is further processed without any other liquefaction technology into clear or opaque juices, but not pulpy juices.